As a gas circuit breaker used in a high-voltage electric system, a so-called puffer type gas circuit breaker is generally used. It utilizes rise of extinguishing gas pressure in the middle of opening to cut off an electric current by blowing compressed gas against arc caused between the electrodes. To improve the breaking performance of the puffer type gas circuit breaker, a double motion method to drive a conventionally-fixed driven side electrode in an opposite direction to a driving direction of the driving side electrode, is proposed.
For example, Patent Literature 1 proposes a method using a fork-shaped lever. According to this invention, practically, when a pin interlocked with the movement of the driving side comes into contact with a depression of the fork, the fork-shaped lever is rotated. The rotation is converted into reciprocating motion in an opening/closing axis direction, to drive the driven side arcing contact in an opposite direction to a driving direction of the driving side electrode. In a state where the pin is away from the depression of the fork, the position of the lever is maintained, and the driven side arcing contact stands still.
Further, Patent Literature 2 discloses a gas circuit breaker in which “a grooved cam having a groove is fixed to the connecting rod. A connecting pin of a link mechanism is slidably engaged and slid in the groove, with which a link is rotated, to displace an opposing arcing contact in an opposite direction to a moving direction of the movable arcing contact.” (See Abstract).